Air cleaner



P 1933- F. A. DONALDSON 1,926,841

AIR CLEANER Filed May 26, 1952 2 Sheets-Sheet 1 6 /rN /7/0r Fen/v" A. OOAMLDJON By his A //o/'n eys 3 buretor of an automobile Patented Sept. 12, 1933 UNITED STATES PATENT OFFICE AIR CLEANER Frank A. Donaldson, Minneapolis, Minn. Application May 26, 1932. i Serial No. 613,603

.. 6 Claims. (01. 1ss-1o) My present invention relates to air cleaners that are capable of very general use, but are especially adapted for use with internal combustion engines such, for example, asjthose employed in connection with the engines of automobiles, tractors, harvesting-machines, and generally all internal combustion engines which are used where the air is laden with dust.

Generally stated, the invention consists of the novel devices, construction and combination of parts hereinafter described and deflned in the claims.

Although not limited to any particular type of aircleaning element, the present air cleaner has been especially designed for use in connection with dust-intercepting air-cleaning screens of the type disclosed and broadly claimed in the application of Wilfred W. Lowther, S. N. 551,883, filed July 20, 1931 and entitled Air cleaner. In connection with the drawings, 1 have in several instances illustrated air-cleaning screens or elements of the novel type disclosed in the application of William H. Schulz, "filed June 13, 1932 S. N. 616,860 and entitled Air cleaner.

In the accompanying drawings, which illustrate the invention and wherein like characters indicate like parts throughout the several views:

Fig. 1 is a fragmentary side elevation showing the improved air cleaner connected to the carengine of the internal combustion type;

Fig. 2 shows the improved air cleaner chiefly in vertical axial section, but with some parts in full and some parts broken away;

Fig. 3 is a fragmentary view corresponding to Fig. 2, but illustrating a modified form of the air-cleaning screens or elements; and

"Fig. 4 is a view corresponding to Fig. 3 but illustrating a still different form or arrangement of the air-cleaning screens.

Referring first to the construction illustrated in Figs. 1 and 2, the numeral 5 indicates the internal combustion engine having ordinary or standard carburetor 6, and in accordance with automobile construction, arranged behind the automobile radiator '7 and under the hood 8. The

air intake tube 6 of the carburetor 6 is shown as of the type offset from the body of the carburetor and extended upward. The outer shell or casing of the improved air cleaner is madeup or two sheet metal sections 9 and 10 and the clean air outlet tube 11 of the air cleaner is in the form of a cy" drical tube ain'ally extended downward from within the'casing and telescoped onto the upper end of the carburetor air intake tube 6.

Near its upper end, the air outlet tube 11 is provided with an integrally formed outstanding annular rest flange 12 having a pliable gasket 12' seated thereon. Rigidly secured in the upper end of said tube 11 is a spider like bracket 13 which, for a purpose that will presently appear, is provided with an axially located upwardly projecting threaded bolt 14 equipped with a thumb nut 15.

The bottom of the lower case section 9 is formed to afford an annular oil well 16, from the inner edge of which oil well a sheet metal cylindrical skirt 1'7 extends upwardly into the casing. This skirt 17 is concentrically spaced from the tube 11 and its upper end is contracted to form an inwardly projecting annular flange 18 that seats upon the outer top'surface of the rest flange gasket 12 Near its flanged upper end, the skirt 1'1 is provided with a plurality of. air passages 19.

The upper section 10 of the casing at its lower ,5 edge seats upon the upper edge of the lower section 9 and is provided with a rigidly secured depending annular skirt-like flange 10 that is detachably telescoped into the lower section 9 and seated at its lower edge on a shoulder 9 at the 9 junction of the section 9 and oil well 16. The top of the case section 10 is in the form of a head 10, that closes the top of the casing. Secured to and depending from the head 10 is a cylindrical sheet metal skirt 20 that is provided with an inwardly-projecting annular flange 21 that seats upon the flange 18, overlaps the same, and also seats upon the rest flange gasket 12", which gasket prevents leakage of air by or between the flanges 12, 18 and 21. 20 that is below the flange 21 is concentrically spaced from and outward of the skirt 1'1. The skirt 20 extends down close to the surface of the oil y contained in the annular oil well 16 and divides the casing into two chambers a and b. The skirt 17 forms, between the clean air outlet tube 11 and the skirt 20, an annular air intake conduit that extends vertically upward to the air ports 19 and from thence vertically downward. to or approximately to the surface of the oil. The importance of this will be later considered. In the extreme upper portion of the skirt 20, above the flange 21, are large clean air outlet ports 23.

The lower section 9 of the casing is directly supported from the rest flange 12 through the skirt 17. When the two case sections 9 and 10 are telescoped together, the bolt 14 will be passed through an axial bolt passage in the top of the head 10 and when the nut 15 is applied, as shown in the drawings, the two'ease sections will be no That portion of the skirt 0 I firmly held together and firmly clamped to and supported from the rest flange 12.

The screen or dust-intercepting element will be placed in the annular compartment b and as althe dust-intercepting screen is shown as made More specifically,

up of a plurality of tubular annular wire mesh screens 24 that are rectangular in cross-section and are connected at their apexes so that they can be applied and removed as an entirety. This complete annular multiple tube screen is closely but loosely fitted within the annular chamber b of the case and is held in place by soldering or otherwise securing the lower of the screens 24 to the skirts 20 and 10,

In the modified structure illustrated in Fig. 3, the structure is the same as that illustrated in Figs. 1 and 2 except that the intercepting screen is made up of a large number of tubular screen sections 2-1; that are arranged in vertically as well as horizontally aligned and connected sections. As above indicated, the particular form of intercepting screen illustrated in Figs. 2 and 3 are not herein claimed but will be made the subject matter of another application.

The structure illustrated in Fig. 4 is like that illustrated in Figs. 1, 2 and 3 except that in this arrangement the intercepting screens 24 are annular conical screens arranged much like the screens disclosed and claimed in the pending Lowther application, Serial Number 551,884, filed July 20, 1931, and entitled Air cleaner.

Operation From the foregoing it will be observed that as an important feature I have provided what may be designated as an up-draft air cleaner for down-draft carburetors with all of the parts in very compact arrangement, especially in respect to vertical dimensions so that the air cleaner is well adapted for application in the space afforded in the hoods of automobiles and tractor engines. the air cleaner is provided with conduit that leads upwardly through its bottom and thence downwardly to the oil well and thence upwardly through the cleaning screens and from thence downward to the carburetor through the clean air outlet. For compactness and eficiency in action, the several conduits of the air cleaner are in concentric arrangement of the casing.

Applying this description to Fig. 2, for example, the dust-laden air is drawn upward through the annular air intake passage formed between thence through ports sage formed between the skirts 17 and 20; thence against the surface of the oil 1! in annular well 16; thence upward through the screens 24 and through ports 23 to axial clean air outlet tube 11 and to the intake tube 6 of the carburetor. The dust-laden air coming in contact with the oil 1! in well 16 produces a violent agitationof the oil, which will throw the same into a foam or spray that will be carried upward through the screens 24 or at least through some thereof. The oil contacting with the wires of the inclined with the clean air outlet at the axis screens will run downward forming oil films over the openings in the screens and through which films the air must pass on its upward travel toward ports 23. The dust-laden air, moving downward through annular channel a, acquires considerable momentum so that a large part of the dust or solid particles will be directly thrown against the surface of the oil 3 in well 16 while the air and some of the lighter dust which makes an upward turn, will come into contact with the oil films on the screens.

A large part of the dust will be directly taken up and held by the oilbefore the air reaches the screens but the remaining part of the dust or solid particles will be caught by the oil films and washed with the downwardly running oil back into the well 16. By the proper arrangement and number of the inclined surfaces of the screens, an arrangement is provided which will take substantially all of the dust or foreign materials from the air. Also the screens will be of such number and arrangement that no oil will be carried past the screens to the ports 23.

In actual practice, this air cleaner has been found to be very highly eflicient. It is of simple construction and capable of being easily made and applied, Simply by removal of the nut 15 from the bolt 14, the upper section 10 of the caslOU ing is released so that it may be quickly removed and thereby permit the cleaning screens or elements to be readily removed, cleaned and replaced.

From the foregoing it is evident that the air cleaner illustrated is capable of various modifications as to details of construction and arrangement of parts within the scope of the invention herein disclosed and claimed.

What I claim is:

1. In an air cleaner an axially located downwardly opening clean air outlet tube provided with an outstanding rest flange, a casing provided in its bottom with an annular oil well and with askirt rising from the inner portion of said well and. having a flange seated upon said rest flange, an outer skirt extended from the top of said casing and dividing said casing into concentric inner and outer chambers, the latter containing an oil intercepting screen, said skirts being spaced from each other and from said axial clean air outlet tube and connected to form an air intake conduit that leads upward from the bottom of said casing and thence downward to said oil well, said clean air outlet tube being in communication -with the upper portion of the screen-containing chamber of said cas 2. The structure defined in claim 1 in which said outer skirt ,is provided with an inwardly projecting annular flange supported from the rest flange of said outlet tube.

3. The structure defined in claim 1 in which said outer skirt is provided with an inwardly projecting annular flange supported from the rest flange of said outlet tube, and a connection between the top of said casing and said outlet tube for anchoring the former to the latter.

4. The structure defined in claim 1 in which said outer skirt is provided with an inwardly projecting annular flange supported from the rest flange of said outlet tube, said casing being formed with a removable upper section that carries with it said outer skirt and its inwardly projecting flange.

5. The structure defined in claim 1 in which said outer skirt is provided with an inwardly pro- ,iecting annular flange supported from the rest flange of said outlet tube, said casing being formed with a removable upper section that carries with it said outer skirt and its,inwardly projecting flange, a spider connected to the upper end of said air outlet tube and provided with an upwardly projecting anchoring bolt extended through the top of said casingand provided with a nut for holding the sections of the casing together and anchoring the same to the rest flange of said outlet tube.

6. The structure defined in claim 1 in which said outer skirt is provided with an inwardly projecting annular flange supported from the rest flange of said outlet tube, said casing being formed with a removable upper section that carries with it said outer skirt and its inwardly projecting flange, a spider connected to the upper end of said air outlet tube and provided with an upwardly projecting anchoring bolt extended through the top of said casing and provided with a nut for holding the sections of the casing together and anchoring the same to the rest flange of said outlet the, and a gasket interposed between the annular flange of said outer skirt and the rest flange of said outlet tube.

'1. The structure defined in claim 1 in which screen chamber, said said outer skirt 'is provided with an inwardly projecting annular flange that is seated onthe said flange oi the inner skirt, said casing being formed with a removable upper section that carries with it said outer skirt and its inwardly projecting flange, and a connection between the top of the casing and outlet tube for detachably clamping the flanges of the inner and outer skirts together and against the rest flange.

8. In an air cleaner, 9. clean air outlet tube, an inner skirt spaced from but surrounding said outlet tube, an outer skirt spaced from but surrounding said inner skirt, a casing surrounding and enclosing said two skirts and the upper end portion of said air outlet tube, said inner skirt and easing being joined at their lower portions to form an annular oil well, said outer skirt and casing forming an annular screen chamber that is connected to the upper end of said air ou'tlet tube, and an annular screen interposed in said two skirts affording an air inlet tube that leads upward and thence downward to said oil well. said screen in said screen chamber being made up of tubular wire members having inclined surfaces.

A. DONALDSON. 

